Seven thousand seismograms of small earthquakes in the Mammoth Lakes-Bishop area were used to measure values of Q from the decay of the earthquake coda. These measurements were compared between events that occurred before and after the Round Valley earthquake (M=5.7). We found that in regions near the main shock epicenter, measurements of coda Q-1 for earthquakes that occurred after the main shock were higher than for those earthquakes that occurred prior to the main shock. The opposite behavior was found for regions farther away from the main shock, namely, lower coda Q-1 after the main shock than before. Measurements of coda Q-1 in the Long Valley caldera, outside of the immediate source region of the earthquake, were higher than in surrounding areas before the main shock, but the difference disappeared after the occurrence of the main shock. This indicates that the temporal variation in coda Q-1 is comparable to its spatial variation. The doughnut model (seismicity quiescence surrounded by a zone of activity) which was invoked for explaining the precursory seismicity pattern appears to be similar with the observed coda Q-1 variation associated with the Round Valley earthquake. The observed spatial variations in coda Q-1 also help to reconcile conflicting results published in previous studies of the coda Q-1 precursor. ¿American Geophysical Union 1987